Q.1.  Refrigerator is not cold enough and I see ice building up in my frost free freezer.
A:  Most newer refrigerators use electronic devices to control the defrost system. If your refrigerator does not have a defrost timer, do not attempt this diagnosis procedure.
1) Unplug the refrigerator.
2) With the freezer frozen down, (it must have been running at least a couple of hours to give the contacts in the defrost thermostat a chance to get cold and close) remove the evaporator cover (the cover in the freezer that covers the cooling coil)
3) Plug the refrigerator in.
4) Locate the defrost timer and, with a screw driver, turn the timer to the defrost mode. ( There is a slot on the timer that the screwdriver will fit in. Turn it clockwise. The refrigerator will stop running when it goes into the defrost mode.)
5) Wait about 5 minutes, then see if the defrost heater is heating. It will get VERY HOT, so be careful! If it is heating, the defrost heater and defrost thermostat are good. The timer should be replaced.

Q.2.  Refrigerator freezes everything even when set on the lowest setting.
A:  It sounds like you have a defective cold control (thermostat).

Q.3. Do you smell ammonia, either inside the refrigerator or outside?
A:  If you smell ammonia either inside the refrigerator or outside of it, the cooling unit is defective will need to be replaced.

Q.4.  Do you see any yellow staining on the back of the unit?
A:  Sodium chromate is a greenish-yellow powder in solution inside the cooling unit. If you see any signs of a greenish-yellow staining outside the cooling unit, your unit has a leak and will need to be replaced.